Laminated cell tab connection structure and lithium battery
Through the laminated battery cell ear connection structure, the complex problem of the electrode ear and electrode welding process of traditional lithium battery cells is solved, and the effect of reducing the number of welding times and improving the quality of the battery cell is achieved.
Patent Information
- Application Number
- CN202421606592.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-08
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-08
AI Technical Summary
The electrode ear and electrode sheet welding process of traditional lithium batteries is complex and requires multiple welding, resulting in high scrap rate and high battery cell cost.
The laminated battery cell ear connection structure is adopted, and the laminated sheet is formed by spacing the laminated sheets through the positive stacking unit and the negative stacking unit. The laminated frame beam is welded to the battery cell cover plate through a set of welding points.
Reduces the number of welding times, reduces the production process and battery cell cost, and improves the yield and quality of battery cell.
Smart Images
Figure CN222927728U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of lithium battery stacks, and in particular relates to a stacked battery core pole ear connection structure and a lithium battery. Background Art
[0002] In the traditional lithium-ion battery structure, the lithium battery's tabs (including positive tabs and negative tabs) and pole pieces (including positive electrode pieces and negative electrode pieces) are fixedly connected at the same position.
[0003] The welding method of pole pieces and pole tabs is generally divided into two steps: the first step is to use an ultrasonic welding device to perform preliminary welding on all the superimposed pole piece foils to achieve preliminary bonding of the pole piece foils; the second step is to use an ultrasonic welding device again to firmly weld the preliminary bonded pole piece foils to the metal pole tabs of the battery cell.
[0004] The internal cells and tabs of lithium batteries are usually welded with adapters during the manufacturing process. During the assembly process, two or even three welding steps are usually required, involving multiple welding methods. The manufacturing process is complicated and the scrap rate is high. At the same time, the cost of the cells is also relatively high. Utility Model Content
[0005] In view of the above problems, the utility model proposes a laminated battery core tab connection structure, including a positive stacked core unit and a negative stacked core unit, each of which has a plurality of positive stacked core units, wherein:
[0006] Each positive stacked core unit includes a first positive electrode sheet and a first negative electrode sheet, which are arranged symmetrically from left to right and connected to each other through positive electrode tabs to form a V-shaped structure;
[0007] Each negative-stage stacked core unit comprises a second positive electrode sheet and a second negative electrode sheet, which are arranged symmetrically from right to left and connected by a negative electrode tab to form an inverted U-shaped structure;
[0008] The positive-stage stacked core unit and the negative-stage stacked core unit are spaced apart by stacking sheets in the thickness direction to form a square frame structure in the shape of a square, and a cross beam of the square frame is welded to the cell cover plate through a group of welding points.
[0009] Preferably, a positive welding point is arranged on the positive electrode tab, and a negative welding point is arranged on the negative electrode tab, and the positive welding point and the negative welding point are welded to the battery cell cover plate.
[0010] Preferably, the weld marks formed by the negative welding point and the positive welding point are circular, and the diameters are both d, and d≥6mm.
[0011] Preferably, the cell cover plate is an aluminum plate, and the cell cover plate is provided with an overcurrent protector, the overcurrent protector is arranged in correspondence with the negative welding point and the positive welding point, and the area of the overcurrent protector is larger than the weld area.
[0012] Preferably, the total number of stacked sheets of the positive stacked core unit and the negative stacked core unit is L, and L≥30 is satisfied.
[0013] Preferably, the total alignment degree of the stacked sheets of the positive stacked core unit and the negative stacked core unit is less than ±5°.
[0014] Preferably, between adjacent positive stacked core units and negative stacked core units, the stacked sheets are sequentially stacked through diaphragm coating.
[0015] Preferably, the stacked sheets include Z-shaped stacked sheets or cut stacks.
[0016] Preferably, the positive electrode tab and the negative electrode tab are in the structure of long strip sheets, the positive welding point is arranged in the middle of the surface of the positive electrode tab, and the negative welding point is arranged in the middle of the surface of the negative electrode tab.
[0017] This application also claims to protect a lithium battery, and the above-mentioned laminated battery cell tab connection structure is welded to the battery cell cover plate.
[0018] Beneficial effects
[0019] 1. In the prior art, the battery cell and the tab inside the lithium battery are usually welded by using a transfer piece during the manufacturing process. Then, the welded main body is welded to the battery cell cover plate by means of secondary or even tertiary welding. Compared with the present utility model, the positive stacked core unit and the negative stacked core unit are directly stacked at intervals to form a square frame structure in the shape of a mouth, and the cross beam of the mouth-shaped square is welded to the battery cell cover plate through a group of welding points. Firstly, the positive stacked core unit and the negative stacked core unit have already formed semi-finished products, so the setting of the transfer piece is omitted, reducing the manufacturing process. Secondly, through a group of welding points to weld the cross beam of the mouth-shaped square, the positive stacked core unit and the negative stacked core unit are welded uniformly. Therefore, at least secondary or even tertiary welding is also saved, greatly improving the yield rate of the battery cell manufacturing process and enhancing the battery cell quality.
[0020] 2. Further, when the positive stacked core unit and the negative stacked core unit are processed and produced, symmetrical coating is carried out on the left and right during the coating of the negative electrode of the stacked sheets. When laser slitting is performed, the left and right are directly slit symmetrically while keeping the middle tab connected; similarly, symmetrical coating is carried out on the left and right during the coating of the negative electrode of the stacked sheets. When laser slitting is performed, the left and right are directly slit symmetrically while keeping the middle tab connected. Thus, the above-mentioned semi-finished positive stacked core unit and negative stacked core unit are formed, and then the positive stacked core unit and the negative stacked core unit are stacked with each other, and a distance is reserved at the middle tab, that is, the positive electrode tab and the negative electrode tab, to ensure that the tabs can be directly laser welded to the battery cell cover plate.
[0021] Other features and advantages of the present utility model will be described in the subsequent specification, and partly will become apparent from the specification, or will be understood by implementing the present utility model. The objectives and other advantages of the present utility model can be realized and obtained through the structures pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0023] Figure 1 Shows a schematic diagram of the tab connection structure of the laminated battery cell in the embodiment of the present utility model;
[0024] Figure 2 Shows a schematic diagram of the positive laminated core unit in the embodiment of the present utility model;
[0025] Figure 3 Shows a schematic diagram of the negative laminated core unit in the embodiment of the present utility model.
[0026] In the figure,
[0027] 11. Positive laminated core unit; 110. First positive electrode tab; 111. First negative electrode tab; 112. Positive electrode tab; 1120. Positive welding point;
[0028] 12. Negative laminated core unit; 120. Second positive electrode tab; 121. Second negative electrode tab; 122. Negative electrode tab; 1220. Negative welding point. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] In order to make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present utility model.
[0030] Referring to Figure 1 , Figure 1 , which shows a schematic diagram of the tab connection structure of the laminated battery cell in the embodiment of the present utility model; it can be clearly seen from this schematic diagram that a tab connection structure of a laminated battery cell includes a positive laminated core unit 11 and a negative laminated core unit 12, both of which have several, and among them,
[0031] Reference Figure 2 , Figure 2 shows a schematic diagram of a positive stacked core unit in an embodiment of the present invention; it can be clearly seen from this schematic diagram that each positive stacked core unit 11 includes a first positive electrode plate 110 and a first negative electrode plate 111, which are symmetrically arranged from left to right and are connected to each other through a positive electrode tab 112 to form a π-shaped structure;
[0032] Reference Figure 3 , Figure 3 shows a schematic diagram of a negative stacked core unit in an embodiment of the present invention; it can be clearly seen from this schematic diagram that each negative stacked core unit 12 includes a second positive electrode plate 120 and a second negative electrode plate 121, which are symmetrically arranged from right to left and are connected through a negative electrode tab 122 to form an inverted π-shaped structure;
[0033] The positive stacked core unit 11 and the negative stacked core unit 12 are stacked with intervals in the thickness direction to form a square frame structure, and the crossbeam of the square frame is welded to the cell cover through a group of welding points.
[0034] The positive electrode tab 112 and the negative electrode tab 122 are in the shape of long strips. The positive welding point 1120 is arranged in the middle of the surface of the positive electrode tab 112, and the negative welding point 1220 is arranged in the middle of the surface of the negative electrode tab 122. They are welded to the cell cover through the positive welding point 1120 and the negative welding point 1220.
[0035] Moreover, in order to ensure the stability of welding, the weld marks formed by the negative welding point 1220 and the positive welding point 1120 are circular, and the diameter of each is d, and d≥6mm is satisfied.
[0036] Not only that, the cell cover is made of aluminum plate, and the cell cover is provided with an overcurrent protector. The overcurrent protector is arranged corresponding to and in a supporting manner with the negative welding point 1220 and the positive welding point 1120, and the area of the overcurrent protector is larger than the area of the weld mark.
[0037] In the prior art, the internal cell of the lithium battery and the electrode tab are usually welded by using a connecting piece during the manufacturing process. Then, the welded main body is welded to the cell cover by means of secondary or even tertiary welding. Compared with the present invention, the positive stacked core unit 11 and the negative stacked core unit 12 are directly stacked with intervals to form a square frame structure, and the crossbeam of the square frame is welded to the cell cover through a group of welding points. Firstly, since the positive stacked core unit 11 and the negative stacked core unit 12 have already formed semi-finished products, the setting of the connecting piece is omitted, reducing the manufacturing process. Secondly, the crossbeam of the square frame is welded by a group of spot welding points to weld the positive stacked core unit 11 and the negative stacked core unit 12 uniformly. Therefore, at least secondary or even tertiary welding is also saved, greatly improving the yield rate during the cell manufacturing process and enhancing the cell quality.
[0038] In fact, the formation steps of the semi-finished product are as follows. When the positive stacked core unit 11 and the negative stacked core unit 12 are processed and produced, symmetric coating is carried out left and right during the coating of the negative electrode of the laminated sheet. When laser slitting is performed, the left and right symmetry is directly slit, and at the same time, the middle tab is kept connected. Similarly, symmetric coating is carried out left and right during the coating of the negative electrode of the laminated sheet. When laser slitting is performed, the left and right symmetry is directly slit, and at the same time, the middle tab is kept connected. Thus, the positive stacked core unit 11 and the negative stacked core unit 12 of the above semi-finished product are formed. Then, the positive stacked core unit 11 and the negative stacked core unit 12 are stacked with each other, and a distance is reserved at the middle tab, that is, the positive tab 112 and the negative tab 122, to ensure that the tab can be directly laser welded to the cell cover plate.
[0039] Moreover, the total number of stacked layers of the positive stacked core unit 11 and the negative stacked core unit 12 is L, and L≥30 is satisfied.
[0040] To ensure the stability of welding and the final forming rate, the total stacking alignment of the positive stacked core unit 11 and the negative stacked core unit 12 is less than ±5°. Between adjacent positive stacked core unit 11 and negative stacked core unit 12, they are sequentially z-shaped stacked or cut and stacked through diaphragm coating.
[0041] The present utility model also claims to protect a lithium battery, in which the above-mentioned tab connection structure of the laminated cell is welded to the cell cover plate.
[0042] Although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.
Claims
1. A laminated battery cell tab connection structure, characterized in that: It includes a positive-stage stacked core unit (11) and a negative-stage stacked core unit (12), each of which has a plurality of units, wherein: Each positive stacked core unit (11) comprises a first positive electrode sheet (110) and a first negative electrode sheet (111), which are arranged symmetrically from left to right and connected to each other via a positive electrode tab (112) to form a V-shaped structure; Each negative-stage stacked core unit (12) comprises a second positive electrode sheet (120) and a second negative electrode sheet (121), which are arranged symmetrically from right to left and connected via a negative electrode tab (122) to form an inverted U-shaped structure; The positive-stage stacked core unit (11) and the negative-stage stacked core unit (12) are spaced apart in the thickness direction to form a square frame structure in the shape of a square, and the square frame cross beam is welded to the cell cover plate through a group of welding points.
2. A laminated battery core tab connection structure according to claim 1, characterized in that: The positive electrode tab (112) is provided with a positive welding point (1120), and the negative electrode tab (122) is provided with a negative welding point (1220), and is welded to the cell cover plate via the positive welding point (1120) and the negative welding point (1220).
3. A laminated battery core tab connection structure according to claim 2, characterized in that: The weld marks formed by the negative welding point (1220) and the positive welding point (1120) are circular, and both have a diameter d, and satisfy d≥6mm.
4. A laminated battery core tab connection structure according to claim 3, characterized in that: The cell cover plate is an aluminum plate, and the cell cover plate is provided with an overcurrent protector, the overcurrent protector is arranged in a matching manner with the negative welding point (1220) and the positive welding point (1120), and the area of the overcurrent protector is larger than the weld area.
5. The laminated battery core tab connection structure according to claim 1, characterized in that: The total number of laminated layers of the positive-stage laminated core unit (11) and the negative-stage laminated core unit (12) is L, and L≥30 is satisfied.
6. A laminated battery core tab connection structure according to claim 5, characterized in that: The total lamination alignment of the positive-stage stacked core unit (11) and the negative-stage stacked core unit (12) is less than ±5°.
7. The laminated battery core tab connection structure according to claim 1, characterized in that: Adjacent positive-stage stacked core units (11) and negative-stage stacked core units (12) are stacked in sequence through diaphragm coating.
8. A laminated battery core tab connection structure according to claim 7, characterized in that: The laminations include z-laminates or cut-laminates.
9. The laminated battery core tab connection structure according to claim 2, characterized in that: The positive electrode tab (112) and the negative electrode tab (122) are of long strip structure, the positive welding point (1120) is arranged in the middle of the surface of the positive electrode tab (112), and the negative welding point (1220) is arranged in the middle of the surface of the negative electrode tab (122).
10. A lithium battery, wherein the laminated battery cell tab connection structure according to any one of claims 1 to 9 is welded to a battery cell cover.